Herpes simplex – Immunity Serology

Testing Indications

Serologic testing is indicated for determining evidence of past infection with HSV and is not indicated for the diagnosis of acute/recent HSV infection where virus detection from active lesions is the test of choice.  If infection or recent exposure is suspected it is preferable to submit samples for virus detection see Herpes Simplex – conjunctival, CSF or Herpes Simplex – Skin and Genital.

Following infection with HSV, it may take up to 3 to 6 months for HSV IgG antibodies to be detectable in serum/blood.

Specimen Collection and Handling

Specimen Requirements

Test Requested Required Requisition(s) Specimen Type Minimum Volume Collection Kit

Herpes Simplex IgG

Whole blood or serum

5.0 ml (blood) or 1.0 ml (serum)

Blood, clotted - vacutainer tubes (SST)

Herpes Simplex IgG

Plasma

1.0 ml

EDTA / Lavender top tube

Submission and Collection Notes

1

Type-specific HSV IgG serology (differentiation of HSV Type-1 IgG from HSV Type-2 IgG using serum or plasma) is not performed by PHO laboratory.

2

In order to determine which type of HSV is responsible for a patient’s infection submission of a sample collected from an active lesion for virus detection is required.  If the virus is detected typing is performed using the isolate. Please refer to Herpes simplex – Conjunctival; Herpes simplex – CSF and Herpes simplex Virus (HSV) – Skin (including Genital)

Limitations

Haemolyzed, icteric, lipemic or microbially contaminated sera or plasma are not recommended for testing.

Preparation Prior to Transport

Label the specimen container with the patient’s full name, date of collection and one other unique identifier such as the patient’s date of birth or Health Card Number. Failure to provide this information may result in rejection or testing delay.

Special Instructions

Centrifuge if using SST. Place specimen in biohazard bag and seal. Specimens should be stored at 2-8°C following collection and shipped to PHOL on ice packs.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

HSV IgG serology is performed daily Monday to Friday. 

Turnaround time for test results is up to 5 days from receipt by PHO Laboratory

Reporting

Results are reported to the ordering physician or health care provider as indicated on the requisition.

Test Methods

The Herpes Simplex IgG test is performed using an ELISA (Enzyme Linked Immunosorbent Assay) test kit manufactured by Euroimmun Diagnostics (Germany). This ELISA test provides a quantitative in vitro assay for human antibodies of the IgG class against HSV 1/2 (group specific) viruses in serum or plasma.

Note: This test does not differentiate between HSV Type 1 and HSV Type 2 IgG antibodies.

Interpretation

The presence of HSV IgG antibody (in asymptomatic persons) provides an indicator of past infection with either HSV Type 1 or Type 2. 

IgG antibody levels may be reported as Non-Reactive (no detectable antibody), Indeterminate (the level of antibody detected is considered borderline reactive or equivocal) or Reactive (antibody is detectable within the positive range of the assay).

Please be aware that a non-reactive IgG level does not always indicate the absence of current infection. It may take up to 3 to 6 months for HSV IgG to develop after exposure especially if a patient has been treated with antiviral medication.

In symptomatic patients indeterminate levels of antibody may indicate rising antibody levels following acute infection. In asymptomatic patients indeterminate levels of antibody may be due to genuinely low levels of IgG antibody many years after the initial infection.

contact lab

Contact Laboratory Customer Service

Laboratory Services

customerservicecentre@oahpp.ca

Updated 12 April 2019